1. Field Of The Invention
This invention relates to a stepper, more particularly to a stepper that is provided with a sensor system which is capable of monitoring exercise performance and which can generate corresponding exercise information.
2. Description Of The Related Art
It is important when exercising to have some monitoring or feedback of the exerciser's progress or performance. Information such as the distance traveled or the speed is essential. In the case of a conventional stepper, information, such as the total number of steps and the average number of steps per minute, is required by the exerciser. Referring to FIG. 1, a conventional stepper is shown to include a frame assembly (A), two foot-pedal arms (B), a sensor unit (C) mounted operatively on the frame assembly (A), and an instrument control unit (D) connected electrically to the sensor unit (C) so as to process signals from the latter in order to calculate the above information and display the same on an LED or LCD thereof. Each of the foot-pedal arms (B) is mounted pivotally on the frame assembly (A) at one end thereof. A magnet (M) is provided on one of the foot-pedal arms (B) and moves synchronously with said one of the foot-pedal arms (B). The sensor unit (C) is a magnetic reed switch which is mounted operatively on the frame assembly and which is operated or activated when the magnet (M) passes close thereto. That is, supposing that the reed switch is originally "OFF", the reed switch is turned on when the magnet (M) passes close thereto. Thus, the instrument control unit (D) receives information regarding how many times the reed switch was turned off or on to enable the former to calculate the desired exercise information and display the same on an LED or LCD.
The use of a reed switch in the stepper results in the following drawbacks:
1. Since the reed switch is mechanical and has moving parts, breakdown or failure of the reed switch is likely to occur after prolonged use of the stepper. PA1 2. The reed switch is not activated if the magnet does not pass close enough thereto, thereby resulting in the provision of inaccurate electrical signals to the instrument control unit (D). PA1 3. The reed switch serves as a counter since it can only generate "ON" or "OFF" signals. Thus, some exercise information, such as the amount of calories consumed, cannot be determined accurately because this requires additional information which the reed switch cannot provide, like the angular movement of the foot-pedal arms. PA1 4. When the reed switch is in use, the speed of the angular movement of the foot-pedal arms cannot be detected. Thus, a slow short rotation of the foot-pedal arms cannot be distinguished from a fast long rotation of the same. Therefore, the amount of exercise effort determined is inaccurate since the above information are also required to achieve a precise calculation.